Some makes and material works better then others, more efficient. APC is a much more efficient than a MAS. If you are off to the side of a running engine, {not a great idea but it happens} and the engine is brought up to full RPM you can see the MAS flex due to the material it's made of, that robs power. No prop is made or designed to be hitting the ground but I use MAS on trainers and they last a very long time even with all the ground strikes. Other then that I don't use them. Wood props are usually lighter and will spool up faster but some engines, for the most part four strokes, will idle better with a prop with more weight. There are a number of good articles writen about props and there selection. If you are breaking props then you are doing something wrong, they are made to move air, not dirt. I did at one point teach three people to fly using the same old trainer and I only used the one MAS prop. I think that was some sort of record!!